<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<style type="text/css">
				.box{
					width: 500px;
					height: 500px;
					background: green;
					display: flex;
					flex-direction: column;/*改变主轴为垂直方向*/
					justify-content: space-around;
				/*	align-items: center;*/
				}
				
				.one{
					width: 100px;
					height: 100px;
					background: red;
					/*margin: auto;*/
				}
			</style>
		</head>
		<body>
			<div class="box">
				<div class="one">1</div>
				<div class="one">2</div>
				<div class="one">3</div>
				<div class="one">4</div>
			</div>
		</body>
</html>
